Upper bounds for alpha-domination parameters

In this paper, we provide a new upper bound for the alpha-domination number. This result generalises the well-known Caro-Roditty bound for the domination number of a graph. The same probabilistic construction is used to generalise another well-known upper bound for the classical domination in graphs. We also prove similar upper bounds for the alpha-rate domination number, which combines the concepts of alpha-domination and k-tuple domination.Comment: 7 pages; Presented at the 4th East Coast Combinatorial Conference, Antigonish (Nova Scotia, Canada), May 1-2, 200

On Roman, Global and Restrained Domination in Graphs

In this paper, we present new upper bounds for the global domination and Roman domination numbers and also prove that these results are asymptotically best possible. Moreover, we give upper bounds for the restrained domination and total restrained domination numbers for large classes of graphs, and show that, for almost all graphs, the restrained domination number is equal to the domination number, and the total restrained domination number is equal to the total domination number. A number of open problems are posed. © 2010 Springer

Heating controls: International evidence base and policy experiences

This report presents a synthesis in the form of narrative summaries of the international evidence base and policy experiences on heating controls in the domestic sector. The research builds on the former Department of Energy and Climate Change (DECC) commissioned (systematic) scoping review of the UK evidence on heating controls published in 2016 (Lomas et al., 2016), and the Rapid Evidence Assessment of smarter heating controls published in 2014 (Munton et al., 2014). The report consists of two parts. Part 1 involves a (systematic) scoping review of the international evidence base on the energy savings, cost-effectiveness and usability of heating controls in the domestic sector. Part 2 contains the findings from an analysis of the policy experiences of other countries

Design for safety in construction in Sub-Saharan Africa: A study of architects in Ghana

Design for safety (DfS) is an important mechanism for addressing accidents in construction. In the main, DfS studies have largely focussed on various regions of the world other than sub-Saharan Africa (SSA). Through a questionnaire survey, this study investigated the DfS awareness and practice amongst architects in the Ghanaian construction sector. Data analysis revealed that there is a low engagement in DfS practice despite a high level of awareness of DfS amongst architects. There is a high interest in DfS training juxtaposed against a low engagement in DfS training. DfS practice is not associated with: awareness of the concept of DfS; engagement in DfS professional development training; receipt of DfS education; membership of professional body; years of experience in role; and the company size. Concerted efforts by industry stakeholders, including clients, educational institutions and design professional bodies would be required to encourage the application of DfS amongst architects and other design professionals within the Ghanaian construction environment. Furthermore, more studies on DfS within the SSA context are required in order to profile DfS awareness and practice amongst design practitioners and other industry stakeholders within the region

Design for safety implementation factors: a literature review

© 2018, Emerald Publishing Limited. Purpose: Decisions made during the design stage of construction works can significantly reduce the risk of occurrence of occupational accidents, injuries and illnesses. Moreover, it has been established that design is one of the major contributors of accidents and injuries. Design for safety (DfS) studies within construction have highlighted factors affecting the implementation of DfS, among which are designer attitude; DfS knowledge/awareness and education; availability of DfS tools, including guidance; client’s influence and motivation; and legislation. The purpose of this study is to carry out an in-depth literature review of DfS studies within construction to explore the extent to which existing DfS research has looked at the above-listed DfS implementation factors. Design/methodology/approach: A review of 164 journal articles related to DfS in construction (published from 1990 to 2017) within built environment, engineering and multidisciplinary safety journals was undertaken. Findings: The findings indicate that around 60 per cent of the journal articles reviewed address designer knowledge/awareness and education issues, about 27 per cent looked at DfS implementation tools to assist designers to undertake DfS, about 23 per cent studied client influence/motivation, about 16 per cent studied designers’ attitudes towards DfS implementation and approximately 16 per cent looked at the role of legislation in DfS implementation. The literature points that client influence/motivation and legislation are very influential DfS implementation factors despite a limited number of studies in these areas. Originality/value: Overall, the findings provide an indication of areas of DfS implementation, particularly client influence/motivation and legislation, where more research would be needed to promote DfS in construction to help mitigate the occurrence of accidents and injuries

Making energy behaviour research relevant to policy: A tale of two studies

Within a context of shrinking government resources and greater pressure on academics and other researchers to generate ‘impact’ from (publically funded) research there is a greater need than ever to ensure that published research is readily usable by and relevant to policy end-users. Through examining and comparing two energy related evidence reviews commissioned by the UK government, this paper presents a set of recommendations for those researchers who seek to make their publications (in both the white and grey literature) more accessible, usable and relevant to those working in policy and practice domains

Design for occupational safety and health: Key attributes for organisational capability

Purpose: Against the backdrop of the contribution of design to the occurrence of occupational injuries and illnesses in construction, design for occupational safety and health (DfOSH) is increasingly becoming prominent in the construction sector. To ensure that design interventions are safe for construction workers to build and maintain, design firms need to have the appropriate organisational capability in respect of DfOSH. However, empirical insight regarding the attributes that constitute DfOSH organisational capability is lacking. The purpose of this paper, which trailblazes the subject of DfOSH organisational capability in construction, is to address two key questions: what organisational attributes determine DfOSH capability? What is the relative priority of the capability attributes? Design/methodology/approach: The study employed three iterations of expert focus group discussion and a subsequent three-round Delphi technique accompanied by the application of voting analytic hierarchy process.Findings: The study revealed 18 capability attributes nested within six categories, namely: competence (the competence of organisation’s design staff); strategy (the consideration of DfOSH in organisation’s vision as well as the top management commitment); corporate experience (organisation’s experience in implementing DfOSH on projects); systems (systems, processes and procedures required for implementing DfOSH); infrastructure (physical, and information and communication technology resources); and collaboration (inter- and intra-organisational collaboration to implement DfOSH on projects). Whilst these categories and their nested attributes carry varying weights of importance, collectively, the competence-related attributes are the most important, followed by strategy. Originality/value: The findings should enable design firms and other key industry stakeholders (such as the clients who appoint them) to understand designers’ DfOSH capability better. Additionally, design firms should be able to prioritise efforts/investment to enhance their DfOSH capability

Randomized algorithms and upper bounds for multiple domination in graphs and networks

We consider four different types of multiple domination and provide new improved upper bounds for the k- and k-tuple domination numbers. They generalize two classical bounds for the domination number and are better than a number of known upper bounds for these two multiple domination parameters. Also, we explicitly present and systematize randomized algorithms for finding multiple dominating sets, whose expected orders satisfy new and recent upper bounds. The algorithms for k- and k-tuple dominating sets are of linear time in terms of the number of edges of the input graph, and they can be implemented as local distributed algorithms. Note that the corresponding multiple domination problems are known to be NP-complete. © 2011 Elsevier B.V. All rights reserved

Long term individual load forecast under different electrical vehicles uptake scenarios

More and more households are purchasing electric vehicles (EVs), and this will continue as we move towards a low carbon future. There are various projections as to the rate of EV uptake, but all predict an increase over the next ten years. Charging these EVs will produce one of the biggest loads on the low voltage network. To manage the network, we must not only take into account the number of EVs taken up, but where on the network they are charging, and at what time. To simulate the impact on the network from high, medium and low EV uptake (as outlined by the UK government), we present an agent-based model. We initialise the model to assign an EV to a household based on either random distribution or social influences - that is, a neighbour of an EV owner is more likely to also purchase an EV. Additionally, we examine the effect of peak behaviour on the network when charging is at day-time, night-time, or a mix of both. The model is implemented on a neighbourhood in south-east England using smart meter data (half hourly electricity readings) and real life charging patterns from an EV trial. Our results indicate that social influence can increase the peak demand on a local level (street or feeder), meaning that medium EV uptake can create higher peak demand than currently expected